There has been an intensive effort to produce quality silicon on insulator (SOI) semiconductors for purposes of increasing speed, decreasing power dissipation, and improving transient radiation hardness. An important feature in achieving quality SOI semiconductors is to minimize the annealing time temperature product involved in producing the SOI device. This time temperature product required for annealing is significant due to its direct relationship to the redistribution of the doping concentration. As the annealing time is extended for a given temperature, the greater the redistribution of dopants occurs resulting in reducing the quality in performance of the SOI device.
An example of a method of producing an SOI wafer is found in an article by Ohasi, et al., "Improved Dielectrically Isolated Device Integration by Silicon-Wafer Direct Bonding (SDB) Technique," IDEM, Vol. 1, No. 9.1, 1986, pp. 210-213. This article describes wafers being fused together by forming a layer of silicon dioxide on one of the wafers and then placing the wafers such that they are abutting each other. These wafers are then heated in a furnace at approximately 1100.degree. C. for four (4) hours. As a result of the significantly long annealing time required for the bonding to result in the above method, there is a substantial redistribution of dopant materials in the silicon which could result in poor quality devices in the final SOI product.
Because a furnace is typically used in the annealing process for methods such as that described above, a reduction of annealing time is not possible without adversely affecting the quality of the bond between the wafers. This is a result of the practical timing limitations of using a standard furnace annealer which are well known in the art.